Days 6, 13, 20, and 27 of Each Lunar Month This MESSAGE identifies Al-Jumuʿah as the sixth day of each seven-day lunar quarter: the sixth, thirteenth, twentieth, and twenty-seventh days of the visible lunar month. It distinguishes Al-Jumuʿah from the civil weekday called Friday and identifies the following seventh days—7, 14, 21, and 28—as Sabbath positions. The study examines Q 62:9–11, the lunar-day foundations established in earlier MESSAGE publications, the twenty-seventh day of Ramadan and Laylat Al-Qadr, and supporting Qur’anic mathematical proofs. It is limited to identifying Al-Jumuʿah and does not prescribe ritual practice beyond what is written in Q 62:9–11.
Mahmoud Ahmed (Fri,) studied this question.